As a conventionally employed electrodeposited reamer, for example, a lapping reamer disclosed in Japanese Utility Model Laid-Open No. 53427/1985 (filed by Takezawa Seiki) is known.
As shown in FIG. 22, as for the aforementioned reamer A, a work processing portion C provided at an end portion of a reamer body (base metal) B is formed cylindrically over its entire length. The arrangement provided is such that abrasive grains D are electrodeposited on an external peripheral surface of this processing portion C, and an unillustrated pressing member sealed in the processing portion C is screwed in for expanding the diameter by means of a set bolt provided at an end portion so as to set its diameter, thereby obtaining surface accuracy by controlling the electrodeposited abrasive grain size. It should be noted that, in the drawing, reference character E denotes a slit formed in the work processing portion C.
With the above-described electrodeposited reamer tool A, however, since its portion where the processing abrasive grains are electrodeposited, i.e., the work processing portion C, has a cylindrical shape, as mentioned above, it is impossible to provide a large machining allowance for a pre-processing hole which is formed in a work.
In addition, with the above-described electrodeposited reamer tool A, since the surface roughness is adjusted by controlling the processing abrasive grain diameter, it is necessary to set to a small dimension the machining allowance of the pre-processing hole which is formed in the work, in conjunction with the improvement of the surface roughness.
Accordingly, in order to effect precision processing of bores by using the above-described electrodeposited reamer tool A, it is necessary to preprocess the work with pre-processing bores having dimensional accuracy and surface roughness that are close to targets. For this reason, there has been a drawback in that the process for preprocessing becomes very complicated.
In view of the above-described situation, it is an object of the present invention to provide an electrodeposited reamer tool which is capable of effecting precision processing of bores with high efficiency without requiring a complicated preprocessing step.